When you sell an ETF does it always take 3 days to settle, even if you had held the ETF (with no trades) for years? What about buying an ETF? Does the buy always take 3 days to settle? What about mutual funds? Do those take 3 days to settle as well (buying and selling)?
To my knowledge, all these products settle in T+3. Buy/sell is the same. You're buying from the seller, so they settle at the same time.
ETFs are T+3 settlement and that can be a problem in a cash account. In a margin account, broker will lend to you.